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The present invention relates to fluid valves. More specifically, the present invention relates to power circuits for activating and deactivating fluid valves.
Electrically actuated fluid valves are used in many applications, such as for battery-powered faucet valves, for example. These designs present certain design challenges, however, that make the designs difficult to optimize. In battery-powered faucets that use solenoid-latch valves, the energy required to change the state of the valve is substantial. If such a system is designed to use the whole peak output of the battery, its performance begins to deteriorate soon after the battery strength drains to the point where its peak output diminishes. Alternatively, if the system is designed to use less actuation energy, its performance relative to the supply power is lower from the outset. There is thus a need for higher-performance valve control and power electronics that provide and maintain a high level of performance even after the peak output power of the battery begins to diminish.
It is one object of the present invention to provide an improved valve power control arrangement. It is another object of the invention to improve the power circuitry for electrically powered valves.
These objects and others are accomplished by a circuit including a power supply, booster circuitry, and valve control components, where the booster circuit stores energy in one or more capacitors by repeatedly storing energy in an inductor, then discharging the energy through a diode to one or more capacitors. The capacitors are then discharged through the valve control solenoid to change the state of the valve.
In some variations in this embodiment, the charge stored on the capacitors is monitored, and the cycling of the booster circuit is controlled based on the amount of that charge.
In other variations of this embodiment, a transistor is switched on and off to store and release the energy from the inductor.
In still other variations, the capacitors are periodically re-boosted. This compensates for leakage of charge from the capacitor with time, and improves the response time when the valve eventually needs to be actuated.